Expander



June 29; 1937. G, PLMNE 2,085,447

EXPANDER Filed Dec. 5, 1955 r a PI JW ATTORNEY Patented June 29, 1937 UNITED STATES PATENT OFFICE 13 Claims.

This invention relates to tube expanders in general, and particularly to the kind which may be termed as one-directional, self-feeding and automatically releasing tube expanders.

The prime object of my invention is to provide adevice of this kind which will operate in one direction only, thus eliminating the reversing of the device and at the same time saving a considerable amount of time as compared with the operating time of present-day devices.

Another object of my invention is to provide a device by means of which the formation of ridges and flaking of the tubes will be prevented, which ridges and flaking are caused by reversing of the direction of rotation in heretofore used devices.

Another object of my invention is to so construct and arrange my device that the expansion of the tubes to which my device is applied will be perfectly concentric with the tube exterior, and consequently cylindrical, and in which the expander rolls are caused, during operation, to change their position, that is to say, that they are forced to first assume a position angular to the center axis of the tube to be expanded, and gradually are brought to a position parallel with the center axis of such tube at the finish of the expanding operation.

A further object of my invention is to so construct and arrange my device as to assure the proper extent of expansion of any tube of a given diameter and gage, without over-expanding or under-expanding such tube and without putting an undue strain upon the tube sheet.

, Another object of my invention is to so construct and arrange my device as to render the device self-feeding during the expanding operation, and automatically releasing when the proper extent of expansion is reached, thereby preventing over-expansion and the resulting undercutting, and assuring stoppage of the operation when the proper expansion is accomplished.

A further object of my invention is to so construct and arrange my device as to render it extremely simple, but at the same time effective for the purpose intended, so as not to materially increase the manufacturing cost of the present device over the average existing devices.

The foregoing and still further important objects and advantages of the present invention will become more fully apparent from the ensuing description and the accompanying drawing, forming part of my disclosure, but which are by no means intended to limit the same to the actual showing, and in which Fig. 1 represents a partial, longitudinal crosssectional view taken through a preferred form of my device, at the start of the expanding operation;

Fig. 2 is a similar cross-sectional view of my device near the finishing moment of operation;

Fig. 3 is a similar illustration to that of Fig. 2, in which not only an expander roll, but also a belling roll arrangement is shown in their final positions;

Fig. 4 is a top view of my device; and

Fig. 5 is an enlarged plan view of the expander body of my device.

In the figures, numeral 19 denotes a mandrel in the shape of a taper, the upper end I I of which is cylindrical and is provided with a left-hand thread. Above the cylindrical portion is a flange l2, from which extends a square head I3, which latter is designed to be engaged by an instrumentality adapted to impart a clockwise rotation to the mandrel.

In engagement with the threaded cylindrical portion of the mandrel, there will be seen an internally threaded collar l4, provided with a recessed abutting face l5 and a cylindrical spare-out I6, the purposes of which two provisions will be presently evident. The tapered mandrel extends into the expander body H, which comprises a hollow, cylindrical upper structure l8, and a lower cylindrical structure of lesser diameter, indicated at H). The latter is provided with a tapered and rounded-off lower end 29.

Within the hollow cylindrical upper structure l8, there will be observed a cylindrical oscillating member 2!, provided with an external slot L 22 cut on anangle, as clearly seen in broken lines in Fig. 3, and which slot is engaged by a stud 23, fastened within the wall of the upper body member l8. Oscillating member 2! is provided with a central aperture for permitting the unrestricted passage therethrough of mandrel Ill. The upper end of oscillating member I8 is provided with a cylindrical extension 24, adapted to extend into the spare-out l 6 of threaded collar l4.

Oscillating member 2| is held within the hollow upper body portion I8 by means of a plate or cover 25, which is provided with a central, cylindrical opening 26, adapted to receive the cylindrical reduced extension 27 of collar M. The

somewhat raised upper face 28 of cover 25 is restricted operation therewithin of the mandrel, indicated at it in broken lines in Fig. 5. Recesses 39 are intended to accommodate tapered expander rolls 32, while recess 34 is designed to receive the supporting roll 33 for the belling roll 3 The tapers of the rolls correspond to the taper of the mandrel. All of the recesses 38 and Si are so constructed as to allow a portion of the rolls to extend beyond the outer periphery of the lower end it of the expander body. At the Same time, these recesses are so designed as to permit the tilting of the rolls in the manner illustrated in Fig. 1. upper ends at one side of the recesses are broadened, as indicated at 35. The portion above recess SE for the belling roll arrangement is suitably recessed at 35 for the belling roll, which latter preferably rests with its inclined upper face against a suitable abutment 5?.

Oscillating member 2i is provided with sockets or recesses 38, adapted to receive the upper ends of expander rolls 32.

Operation The functions of my device follow those of the heretofore employed devices with some important exceptions. The operation starts with the device arranged in the manner illustrated in Fig. 1, in that the lower end it of the expander body is placed into the tube 39, which latter is first inserted in the tube sheet Q9, so that the end of the tube extends somewhat beyond the tube sheet. At this moment, oscillating member 2! is in its elevated position and. collar it is suspended by the threaded portion l l of mandrel ill.

The mandrelis now caused to turn in clockwise direction and while thus turning, it engages rolls 32 and also the lower roll 33 of the belling roll arrangement. As mandrel it rotates it will cause the rotation of the rolls and of the expander body and will maintain these rolls in their inclined positions. The rotation of the rolls will keep oscillating member 2! in the position shown in Fig. 1. As the operation proceeds, the rolls will expand the tube cylindrically against tube sheet til and as the expansion progresses, mandrel it will gradually feed into the tube and cause a progressive increase in its expansion. This progressive movement continues until the lower end ii of collar it reaches the upper face 32 of oscillating member 2!.

Up to this moment, all rolls are kept in their inclined positions relative to mandrel B, but now the pressure of face ll against face 52 of the oscillating member will cause the latter to move inwards. During this inward movement of oscillating member iii, the latter is caused to turn, due to the arrangement of slot 22 and stud 23, in anti-clockwise direction, whereby rolls 32, the upper ends of which are held in recesses 38 of the oscillating member, are gradually caused to change their position. They will move from their inclined position to a position substantially parallel with mandrel l At the moment this change of positions of the rolls takes place, the expansion operation is finished and is followed by the flaring or belling operation accomplished by belling roll 34 which now comes into action and rolls out the extending edge of the tube over the tube sheet, as clearly seen in Fig. 3.

When the belling operation is completed, mandrel EB finally reaches its extreme end position, at which annular face l5 of collar it engages face 28 of cover 25 and which engagement is sufficient to stop the revolution of collar it to- In order to permit such tilting, the

gether with the mandrel; thus, the collar becomes stationary, while the mandrel continues to turn. It will gradually unscrew itself from the collar, and thereby withdraw from the expander body and disengage the rolls. This release of the rolls allows the unrestricted withdrawal of the expander body from the expanded tube.

The operation of the mandrel is in one direction only and consequently causes a one-directional operation of the rolls. The expansion of the tube is uniform and smooth and does not show any ridges or waves, usually appearing on expanded tubes upon reversal of operation when present-day expanders are employed. Furthermore, the formation of flakes, also due to the usual reversal of the operation, is entirely eliminated, whereby the full strength of the expanded tube is maintained. The easy withdrawal of the device from the expanded tube is an added important feature and presents quite an advantage over existing devices.

A further advantage of the present invention resides in the fact that it prevents what is known as undercuttingby over-rolling or over-expansion. In consequence of the numerous tests conducted with my tool, I have determined the proper amount of expansion required in order to provide a satisfactory joint between the tube and the tube sheet without straining the latter. is again pointed out that with my tool the expansion is cylindrical and not conical, as'is the case when heretofore constructed devices are employed. I have also determined that when the mandrel has reached about seven-eighths of its intended course of operation, the expansion of the tube is ended and that at this moment, the rolls are to be moved from their inclined position to a parallel position in respect to the mandrel, in which position the rolls will produce what may be termed the finishing operation, while at the same time the belling roll will flare the extending tube end to the desired degree.

Inasmuch as the operation of the mandrel, and its progress into the tube to be expanded, is uniform throughout the entire procedure, it is easy to calculate that practically seven-eighths of the time required for the expanding operation is devoted to the actual expansion of the tube against the tube sheet, while the remaining one-eighth of the time is consumed by the finishing and flaring operations. Due to the fact that the mandrel operates in one direction only and does not require stoppage and reversing of its operation, I have found that the saving in time, as compared with previous methods affording inferior results, is about one-third. In other words, my device requires approximately twothirds of the time usually required with presentday tools. r 7

From the description of the operation, it will be readily seen that my device cannot overroll or over-expand the tube or cause undercutting, since it automatically stops and brings the mandrel into releasing position in respect to the rolls when the rolling and belling operation is completed. In order to effectively and correctly expand one, or successively any number of tubes of a given diameter and a given gage, it is only necessary to select and use a tool of the corresponding size, and if the tubes should vary in gage, it is merely required to employ corresponding mandrels'of either larger or small er diameters. While I have chosen to provide a left-han thread upon the mandrel and collar l4, and described therotation'of the mandrel as clockwise, it is quite obvious that by providing a right-hand thread and-turning the mandrel in anti-clockwise direction, the same benefits of a one-directional expanding Operation will result. Oi course, in such event, the position of slot 22 of the'oscillating'member and the widenings 35 and 36 of recesses 39 and 3l,-respectively, have to be reversed. g

The device as depicted in the illustration shows two expander rolls and one bellingroll arrangement. It is obvious, however, that the number and the positionsof the rolls may be changed as may become necessary for the use of my device in connection with different types of work.

'Also, the various arrangements and constructions shown'may be readily altered and improved and I therefore reserve for myself the right to make such changes, and improvements as may be deemed advisable during the; commercialization of my invention.

Having thus described my invention, I claim:

1. In a tube expander, including a mandrel and expander rolls cooperating therewith, means provided with said expander for changing, during operating, the angular position of said rolls in respect to said mandrel.

2. In a tube expander, including a mandrel and cooperating expander rolls, said expander being constructed and arranged to cause angular changes during operation, in positions of said rolls relative to said mandrel.

3. In a tube expander, including a mandrel and cooperating expander rolls, said expander being so constructed and arranged as to cause, during operation, angular positional changes of said rolls relative to said mandrel, and to cause the withdrawal of the latter from its engagement with said rolls upon completion of its operation, Without changing the direction of rotation of said mandrel.

4. In a tube expander, an expander body, a plurality of expander rolls operatively lodged therein, a mandrel in cooperation with said rolls and adapted to revolve in one direction only, means associated with said expander body for changing, during operation of said mandrel, the angular position of said rolls relative to said mandrel, and means associated with the latter for causing its disengagement from said rolls upon completion of operation.

5. In a tube expander, including a mandrel and expander rolls coacting therewith, said expander being constructed and arranged to cause said rolls to assume, at the beginning of their operation, an angular position relative to said mandrel, and to maintain said rolls in that position 'during the major period of operation, and to cause said rolls to assume, during the end period of operation, a position substantially parallel with said mandrel.

6. An automatically releasing, self-feeding tube expander, comprising in combination, an expander body, a plurality of tapered rolls operatively lodged therein, a tapered mandrel passing through said body and in operative engagement with said rolls, means within said body in engagement with said rolls for facilitating the positioning of the latter at different angular relations to said mandrel, and means in operative engagement with said mandrel, and constructed and arranged to cooperate with said rolls positioning means and said expander body, for first actuating said rolls positioning means and for then causing said mandrel to disengage said rolls.

7. In an automatically releasing, self-feeding tube expander, an expander body provided with means for receiving and for permitting the positioning of expander rolls, a plurality of tapered expander rolls in said receiving means, a tapered mandrel passing through said body and in operative engagement with said rolls, means operatively associated with said body and engaging said rolls for facilitating the positioning of the latter relative to said mandrel, means in operative engagement with one end of said mandrel and constructed and arranged to cooperate with said rolls positioning means and said expander body, and adapted to first cause the operation of said rolls positioning means for bringing the rolls from an inclined position to a substantially parallel position relative to said mandrel, and to then cause, upon engagement with the expander body, said mandrel to withdraw from contact with said rolls.

8. In a tube expander, an apertured expander body provided with recesses for receiving and for permitting the positioning of expander rolls, a plurality of tapered expander rolls and a belling roll arrangement in said recesses, an oscillating member operatively associated with said body and in engagement with said rolls, a tapered mandrel extending through said oscillating member and said body and in operative contact with said rolls and having a threaded body portion, a

threaded collar in engagement with said threaded body portion of the mandrel and constructed and arranged to first operate together with said mandrel, to later engage said oscillating member, to

thereafter engage the expander body, and to finally cause the withdrawal of the mandrel from contact with said rolls, while said mandrel is being operated in one direction only.

9. In a tube expander, an apertured expander body having recesses for receiving expander rolls, said recesses being constructed and designed for facilitating the positioning of such expander rolls, a plurality of tapered expander rolls and a belling roll arrangement operatively mounted in said recesses, an apertured oscillating member operatively associated with said body and engaging said rolls, said member being constructed and arranged for facilitating the positioning of said rolls relative to a mandrel, a rotary mandrel having a cylindrical threaded portion and a tapered body extending from the latter, passing through said oscillating member and said expander body and operatively engaging said rolls, a threaded member in engagement with the threaded portion of said mandrel and so constructed and arranged as to first revolve bodily with said mandrel, to then engage said oscillating member, whereby said rollers are gradually brought from an inclined position to a position substantially parallel with said mandrel, to thereafter engage the expander body, cease revolving and become stationary, thereby causing the still revolving mandrel to unscrew itself relative to said threaded member and to move out of engagement with said rolls.

10. In a device for expanding tubes, expander means, adapted to engage the interior of a tube to be expanded, actuating means for said expander means constructed and arranged to operate during the entire operation in one direction only, said expander means being further constructed and arranged to first engage the tube interior at an angle relative to the longitudinal center axis of said actuating means and to finish its function at and assume its releasing position parallel to the center axis of said actuating means.

11. In a one-directional, self-feeding and self releasing tube expander, an expander body provided with rolls, a mandrel operatively engaging the latter and adapted to rotate in one direction only, said rolls being constructed and arranged to change their position angularly, during operation, in respect to said mandrel, said mandrel being constructed and arranged to withdraw from its engagement with said rolls upon completion of its operation, While continuing to rotate in that one direction.

12. In a one-directional, self-feeding and selfreleasing tube expander, an expander body provided with expander rolls, a revolvable mandrel engaging said rolls, the latter being constructed and arranged to operate during the major part of the expanding operation at an angle relative to said mandrel, and to assume during the finishing portion of such operation a position substantially parallel with said mandrel, said mandrel being constructed and arranged to progressively feed into said expander body until the required expansion of a tube to be expanded is reached, and to automatically withdraw from engagement with said rolls the moment the expanding operation is completed.

13. In a one-directional, self-feeding and selfreleasing tube expander, an expander body provided with expander rolls, a revolvable mandrel from and to disengage said rolls at the conclusion of the entire operation period.

GEORGE PLAINE. 

